See the Market Overview below for a more detailed list.
Offset and Interval
give information, where the card shows best average
read and write rates. Entries with preceding *
indicate that the values could not be determined precisely.
Unaligned Read and Unaligned Write
are percentage values calculated from the
highest and lowest
sustained read/write rate during the test run.
These are not necessarily accurate values, but at least
they tell how much the transfer rates differed depending
on the read/write position. Entries maked with preceding *
indicate that the measured values do not match the
actual behaviour of the card.
For general information, see the alignment article.
Average Sustained Aligned | Alignment | Unaligned | ATA Information | |||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Card | Read | Write | Offs. | Int. | Read | Write | Max. Mode | ATA Type | PCMCIA Type | |||||||||
Renice X4 CF SLC 32GB | 96.67MB/s | 659x | 91.22MB/s | 622x | 0 | 32kB | 98% | 93% | UDMA-6 | Fixed | CF-Removable | |||||||
Renice X4 CF SLC 16GB | 98.18MB/s | 670x | 91.17MB/s | 622x | 0 | 32kB | 98% | 93% | UDMA-6 | Fixed | CF-Removable | |||||||
PhotoFast 533x Plus CF 16GB | 83.81MB/s | 572x | 84.26MB/s | 575x | 0 | 32kB | 95% | 88% | UDMA-6 | CF-Removable | CF-Removable | |||||||
PhotoFast 533x Plus CF 32GB | 87.14MB/s | 594x | 79.05MB/s | 539x | 0 | 32kB | 95% | 89% | UDMA-6 | CF-Removable | CF-Removable | |||||||
Transcend UDMA 300x CF 16GB | 51.34MB/s | 350x | 49.70MB/s | 339x | 0 | 16kB | 96% | 63% | UDMA-5 | Fixed | CF-Removable | |||||||
PhotoFast 533x CF 64GB | 84.91MB/s | 579x | 48.67MB/s | 332x | 0 | 32kB | 96% | 91% | UDMA-6 | CF-Removable | CF-Removable | |||||||
PhotoFast 533x CF 32GB | 88.45MB/s | 603x | 47.71MB/s | 325x | 0 | 32kB | 96% | 85% | UDMA-6 | CF-Removable | CF-Removable | |||||||
SONY 300x UDMA CF 16GB | 48.12MB/s | 328x | 47.57MB/s | 324x | 0 | 16kB | 98% | 79% | UDMA-5 | CF-Removable | CF-Removable | |||||||
SONY 300x UDMA CF 8GB | 43.11MB/s | 294x | 46.30MB/s | 316x | 0 | 4kB | 98% | 94% | UDMA-5 | CF-Removable | CF-Removable | |||||||
Lexar Professional UDMA 300x CF 16GB | 47.06MB/s | 321x | 45.66MB/s | 311x | 0 | 16kB | 98% | 78% | UDMA-5 | CF-Removable | CF-Removable | |||||||
Lexar Professional UDMA 300x CF 8GB | 41.82MB/s | 285x | 44.99MB/s | 307x | 0 | 4kB | 98% | 95% | UDMA-5 | CF-Removable | CF-Removable | |||||||
Kingston Ultimate 266x CF 16GB | 47.08MB/s | 321x | 43.75MB/s | 298x | 0 | 16kB | 98% | 81% | UDMA-5 | Fixed | CF-Removable | |||||||
SanDisk Extreme Ducati Edition CF 8GB | 43.00MB/s | 293x | 43.65MB/s | 298x | 0 | * 4kB | * 95% | * 94% | UDMA-4 | CF-Removable | CF-Removable | |||||||
A-Data Turbo 350x CF 16GB | 47.60MB/s | 324x | 42.83MB/s | 292x | 0 | 16kB | 98% | 79% | UDMA-6 | Fixed | CF-Removable | |||||||
SanDisk Extreme IV CF 4GB | 40.08MB/s | 273x | 38.97MB/s | 266x | 0 | 8kB | 99% | 95% | UDMA-4 | CF-Removable | CF-Removable | |||||||
Kingston Ultimate 266x CF 8GB | 44.12MB/s | 301x | 38.74MB/s | 264x | 0 | 16kB | 98% | 95% | UDMA-5 | Fixed | CF-Removable | |||||||
Transcend 266x High-Speed CF 8GB | 45.26MB/s | 309x | 36.60MB/s | 249x | 0 | 16kB | 98% | 96% | UDMA-4 | Fixed | CF-Removable | |||||||
Transcend ULTRA Industrial CF 8GB | 42.90MB/s | 292x | 35.69MB/s | 243x | 0 | 16kB | 98% | 96% | UDMA-4 | Fixed | Standard | |||||||
Verbatim Pro Series 300X (ATP) CF 8GB | 42.88MB/s | 292x | 35.61MB/s | 243x | 0 | 16kB | 98% | 95% | UDMA-4/5? | Fixed | CF-Removable | |||||||
A-Data Turbo 266x CF 8GB | 47.66MB/s | 325x | 29.29MB/s | 200x | 0 | 8kB | 97% | 94% | UDMA-4 | Fixed | CF-Removable | |||||||
Renice X4 CF MLC 16GB | 89.13MB/s | 608x | 27.80MB/s | 189x | 0 | 32kB | 98% | 98% | UDMA-6 | Fixed | CF-Removable | |||||||
SanDisk Extreme III 30MB/s CF 32GB | 33.13MB/s | 226x | 27.18MB/s | 185x | 32kB | 64kB | 98% | 84% | UDMA-4 | CF-Removable | CF-Removable | |||||||
Transcend Ultra Speed 133x CF 32GB | 45.53MB/s | 310x | 22.63MB/s | 154x | 0 | 16kB | 97% | 58% | UDMA-4 | Fixed | CF-Removable | |||||||
TwinMOS Ultra-X CF 300X 4GB | 28.01MB/s | 191x | 21.54MB/s | 147x | 0 | 8kB | 98% | 97% | UDMA-4 | Fixed | CF-Non-Standard | |||||||
Transcend 133x Ultra Speed CF 16GB | 34.26MB/s | 233x | 15.26MB/s | 104x | 0 | 16kB | 92% | 67% | UDMA-4 | Fixed | CF-Removable |
For regular test results, see the UDMA CompactFlash Cross-Comparison or UDMA CompactFlash Test Results .
Alignment | Unaligned | |||||
---|---|---|---|---|---|---|
Card | Offs. | Int. | Read | Write | ||
SanDisk Extreme III CF 16GB | 0 | 32kB | 99% | 76% | ||
SanDisk Extreme III CF 1GB | 1kB | 2kB | 99% | 85% | ||
SanDisk Ultra II CF (2004) 2GB | 5kB | 32kB | 98% | 78% | ||
SanDisk Ultra II CF (2003) 2GB | 0 | 64kB | 94% | 95% | ||
Transcend 120x CF 8GB | 0 | 8kB | 99% | 92% | ||
Transcend 80x CF 4GB | 12kB | 16kB | 99% | 95% |
CF 1.0: Max. PIO-2 (240ns), 7.95MB/s.
CF 2.0: Max. PIO-4 (120ns), 15.89MB/s.
CF 3.0: The new CF PIO modes PIO-5 and PIO-6
and the ATA UDMA modes
UDMA-0 to UDMA-4
were introduced, offering a theoretical limit of about
63MB/s for UDMA-4.
CF 4.0: The remaining ATA UDMA modes
UDMA-5 and UDMA-6
were added, allowing up to about 127MB/s.
CF 5.0: 48-bit commands were added.
This command set allows a transfer block size of up to
32MB compared to 128kB with the previous command set.
This will allow actual transfer rates to come closer
to the theoretical limit.
CF 6.0: The new CF UDMA mode
UDMA-7 (24ns/166M) was added,
allowing up to about 158MB/s transfer rate.
In case you have plans on using CF cards as regular ATA device: For all timings of 100ns or faster (UDMA-5, UDMA-6 and UDMA-7), the CompactFlash specification only allows one device per bus with a maximum distance of 0.15m (6in) from the card connector to the host controller, at 3.3V supply voltage! In addition to that, 80-wire cables must be used for all UDMA modes.
Current UDMA CF Cards and UDMA CF readers support UDMA-5 or UDMA-6, with real-world transfer rates of more than 80MB/s. This is already beyond the theoretical transfer rate of UDMA-4. Current USB 2.0 UDMA CF readers are maxed out at about 32MB/s, less than 40% of the actual card performance.